The poster for the horror film The Last Exorcism uses various design elements to convey the film's genre and themes. The title is prominently displayed in all capital red letters to draw attention and communicate urgency. The main image features the character Nell in an unnatural pose, surrounded by shadows and cracks, suggesting she is being consumed by evil. Her white dress contrasts with the darkness and represents innocence. The tagline "Believe in him" creates suspicion and references religious themes. Overall, the poster intrigues audiences through its shocking imagery and involvement of popular film studios and creators to promote the horror film.